Dupont Tree Replacement & Salmon Pollution

  • Platte Lake. (Photo by Chris Harnish, courtesy of Interlochen Public Radio)

A few months ago, reports started coming in that an herbicide made by DuPont was hurting and killing trees. The Environmental Protection Agency recently ordered DuPont to stop selling the herbicide Imprelis. DuPont had suspended sales shortly before that. The herbicide was used by lawn care companies to kill weeds on lawns and golf courses starting last fall.

Bert Cregg is an associate professor of horticulture at Michigan State University.

He says Imprelis can cause a range of different injuries to blue spruce, Norway spruce and white pine.

“You might see like in a big white pine, you might see a little bit of top growth doesn’t look quite right, you’ll see the twisting and curling, stunting of the top of the tree, in other cases, yeah we’ve seen the tree killed outright.”

This week, DuPont announced a program to process damage claims from property owners. DuPont declined an interview. But in a statement, the company said property owners with approved claims will receive replacement trees – or cash compensation.

DuPont’s also facing a number of lawsuits.

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This is the Environment Report.

Decades ago, residents sued to stop a fish hatchery in northern Michigan from polluting a lake. More than thirty years later, the legal battles have ended and the pollution has been greatly reduced. Here’s more from Peter Payette:

Northern Michigan is home to some of the clearest blue lakes in the world, like Torch, Glen and Crystal.

Once upon a time Wilfred Sweicki says Platte Lake in Benzie County was in that league.

“It was extremely clear, never quite as clear as Crystal or Glen but nearly so.”

Unfortunately for Sweicki and other homeowners on Platte, fishery biologists did something nearby that changed the Great Lakes dramatically.

They planted Pacific salmon in the Platte River.

That was in the late sixties and soon a billion dollar fishery was born.

A hatchery was built and animal waste from millions of fish began pouring into Platte Lake. The waste contained the nutrient phosphorus.


Phosphorous caused algae to bloom, clouding the water and killing a variety of aquatic animals and plants.

It even caused chemical changes in the sediment of the lake bottom that produced milky clouds of a clay-like substance that collects on stones and docks.

Swiecki remembers the change.

“I spent my summers up here when I was a kid…I knew this lake like the back of my hand…went to college…came back up and oh my gosh, it was 1969 and we lost the lake.”

A few years later homeowners sued.

They won but getting the problem under control has been a slow and contentious process.

Over the years, the state has reduced the amount of phosphorous going into the lake and it has cleared up.

Recently, the state and the Platte Lake Improvement Association have made great strides.

For the last year and a half the amount of phosphorous escaping the hatchery has been close to zero.

Gary Whelan oversees the state’s hatchery system for the Department of Natural Resources. Whelan says they didn’t think it was possible to get the discharge levels this low.

“We’re as low as any place I’m aware of in North America.”

The other notable thing about all this is that the dispute ended on a friendly note.

Wilfred Swiecki says the fight was nasty at times. He compares the DNR in the seventies to automobile companies fighting against rules for tailpipe emissions.

But he speaks highly of Gary Whelan. He says under Whelan the state even hired the lake association’s expert witness to be their consultant.

“They had enough faith in his scientific abilities…he’s now our implementation coordinator.”

But the work isn’t entirely finished. Under the settlement agreement the state still has to pay for monitoring of the hatchery for at least another four years.

For the Environment Report, I’m Peter Payette.